Liner hanger



J. R. SOLUM LINER HANGER Nov. 15, 1966 5 Sheets-Sheet 1 Filed Jan. 8, 1964 IN VEN TOR. J/l/WfS A 504 0/14 Nov. 15, 1966 J. R. SOLUM 3,285,345

LINER HANGER J. R. SOL

LINER HANGER Nov. 15, 1966 5 Sheets-Sheet 5 Filed Jan. 8. 1964 27 Fi e 7 35 42 36 I Era 5 United States Patent 3,285,345 LINER HANGER James R. Solum, Los Angeles, Calif., assignor to B & W

incorporated, Torrance, Calif., a corporation of Caliorma Filed Jan. 8, 1964, Ser. No. 336,443 15 Claims. (Cl. 166208) This invention relates to a tool known as a liner hanger which is employed in oil wells and the like for suspending a liner pipe within a well casing previously set within the well bore and, in particular, is directed to a liner hanger having actuating mechanism of a minimal radial thickness for use in close tolerance situations of narrow annular space between the liner pipe and the well casing.

The many uses and functions of the various styles of liner hangers are well known to those skilled in the art. A common use and function is in attaching a liner pipe on the bottom of the liner hanger, running the liner pipe into the oil production zone, and actuating the liner hanger to grip the inner surface of a well casing through which the liner pipe has been run. Under conventional practices, the well casing is usually of medium size and known as the intermediate string. In order to minimize cost without sacrificing production volume capabilities, it is highly desirable that the intermediate string be of a size no larger than is absolutely necessary for running the preselected size of liner pipe therethrough or, conversely, the liner pipe is the largest size capable of running through the intermediate string. As an example, .a recent desired capability is to use a 5" outside diameter liner pipe with a 7" outside diameter intermediate string casing. It is, of course, highly desirable that the inside diameter of the liner hanger be substantially equal to the inside diameter of the liner pipe and, therefore, the annular space for accommodating the actuating and setting means of the liner hanger may be very minimal.

In many situations the liner pipe will be suspended within an uncased or open hole and will be cemented in place and subsequently perforated. It is usually desirable to condition the open hole well bore and the drilling fluid therein before and during the early stages of the cementing and this may be accomplished by scratchers and similar devices mounted on the liner pipe requiring rota-- tion or reciprocation for their operation. While it is undesirable for the liner hanger to become set during such rotation or reciprocation thereby preventing further rotation or reciprocation, it is highly desirable that the liner hanger be readily and easily set at the completion of the cementing to avoid having the liner pipe become stuck by the cement without actually being hung from the set liner hanger.

Accordingly it is a principal object of this invention to provide a novel form of liner hanger wherein the actuating and setting means require a very minimal radial thickness whereby the hanger may be advantageously employed in close tolerance situations.

Another object of this invention is to provide a novel form of liner hanger assembly having novel means for actuating and setting casing-engaging slips that are operated by simple predetermined rotary and reciprocal movements. A further object of this invention is to provide such a liner hanger wherein a predetermined amount of right-hand rotation is necessary before the casingengaging slips may be set and mere lifting of the liner will unset the slips and permit continued lowering of the Patented Nov. 15, 1966 liner hanger having novel actuating and setting means wherein frictional-drag means for engaging the interior of the well casing are employed for accomplishing relative rotation and reciprocation to perform the setting and unsetting of casing-engaging slips.

A still further and more detailed object of this invention is to provide a novel liner hanger construction wherein the various actuating and setting means are of such minimal radial thickness as to be appropriately mounted on the tubular mandrel of the liner hanger in which the tubular mandrel may be of the same nominal size and material as the liner pipe.

Other and more detailed objects and advantages of this invention will appear from the following description and the accompanying drawings, wherein:

FIGURE 1 is an elevation view of the liner hanger of this invention appropriately set within a well casing with a liner pipe suspended therefrom.

FIGURES 2a and 2b are an enlarged elevation view of the liner hanger of this invention with the components thereof in their respective positions for and during lowering of the liner hanger and liner pipe into the well, FIG- URE 2a showing the upper portion of the liner hanger and FIGURE 2b being a continuation thereof and showing the lower portion of the liner hanger.

FIGURE 3 is a fragmentary elevation of the lower portion of the liner hanger illustrating the respective positions of components after a short upward movement of the liner hanger and before any rotation.

FIGURE 4 is an elevation view similar to FIGURE 3 illustrating the respective locations of the components after a few revolutions of the liner hanger but before the released condition is reached for setting the casing-engaging slips.

FIGURES 5a and 5b are an elevation view of the upper and lower portions, respectively, of the liner hanger with the components in an intermediate position after further rotation from the condition illustrated in FIGURE 4 and after lowering the liner hanger a short distance but before setting of the casing-engaging slips.

FIGURE 6 is an elevation view of the upper portion of the liner hanger after further lowering thereof from the condition illustrated in FIGURE 5a and illustrating the casing-engaging slips in their set position.

FIGURE 7 is an elevation view of the lower portion of the liner hanger illustrating the respective positions of the components after lifting of the liner hanger from the set position illustrated in FIGURE 6 to return the components of the liner hanger to substantially the positions illustrated in FIGURES 2a and 2b for continued lowering of the liner hanger into the well. In the afore-described FIGURES 2a, 2b, 3, 4, 5a, 5b, 6 and 7, the left-hand side of the liner hanger in each figure is sectioned for clarity of illustration of the components and except where hereinafter noted, the left-hand and right-hand portions are identical.

FIGURE 8 is a sectional plan view taken through the retracted casing-engaging slips substantially on the line 8-8 as shown in FIGURE 2a.

FIGURE 9 is a perspective view of one of the casingengaging slips employed in the liner hanger of this invention.

FIGURE 10 is an elevation view of the liner hanger of this invention used in combination with a unique setting tool for permitting the accomplishment of certain operations before setting the liner hanger.

FIGURE 11 is a fragmentary elevation view of a portion of the liner hanger taken substantially on the line 11-11 shown in FIGURE 2a.

Throughout the drawings, the lateral (radial) size, thickness, clearance, etc. of the various components of the liner hanger have been substantially exaggerated from that which is necessary for operational and structural strength. This has been done for clarity of illustration due to the extreme radial thinness and close spacing of some of the components of the actual operational device for use in close tolerance situations and it will readily appear to those skilled in the art from the following description that the numerous components of liner hanger may be made proportionally thinner from that which is illustrated when a close tolerance device is desired.

Referring now in further detail to FIGURES 1, 2a and 2b, the liner hanger, generally designated 10, of this invention has a liner pipe 11 connected to the lower end for suspending the liner pipe within a well bore 12 by setting the liner hanger within a well casing 13. The liner hanger and depending liner pipe 11 are lowered into the casing 13 by a tubing string or drill pipe 14 conneeted to the upper end of the liner hanger 10 by a releasa'ble connector, generally designated 15. After the liner hanger 10 has been set in the well casing 13 to suspend the liner pipe 11 from the bottom of the well bore 12, the drill pipe 14 is appropriately operated to actuate releasable connector 15, thereby releasing the drill pipe from the liner hanger. The drill pipe with the releasable connector then is removed from the well leav- .ing the apparatus in the condition illustrated in FIG- URE 1.

The releasable connector 15 may be of any convenient form for supporting and driving the liner hanger 10 during reciprocation and rotation of the liner hanger and adapted to be released from the liner hanger when desired aftersetting of the liner hanger. The releasable connector 15 includes a collar 16 having an upper internal thread 17 connected to an external thread on the lower end of drill pipe 14. A tubular member 18 is con nected to and extends downwardly from the inside of collar 16. A ring 19 is supported on a shoulder 20 of the member 18 and ring 19 cooperates with collar 16 vto form a ball thrust bearing 21 therebetween. The lower external surface 22 of tubular member 18 is of a noncircular cross-section, such as hexagonal, for cooperating with a threaded bushing 23 slidably supported thereon. An upwardly facing shoulder 24 on tubular member 18 engages threaded bushing 23 for limiting the relative downward movement of the threaded bushing. Bushing 23 is threadedly connected by left-handed threads to the upper end of the tubular mandrel 25 of the liner hanger 10. With the liner hanger 10 and liner pipe 11 suspended in this manner from drill pipe 14 through connector 15 and the liner hanger unset, the frictional forces at the threaded connection between bushing 23 and mandrel 25 are of suchmagnitude as to prevent unthreading of bushing 23 upon right-handed rotation of drill pipe 14 and therefore the liner hanger 10 will likewise be rotated. This is particularly true in that the force required to rotate liner pipe 11, which would tend to resist rotation 'by the drill pipe 14 through connector 15 to cause unthreading of bushing 23, are eliminated by employing a swivel connector, generally designated 26, for connecting the lower end 27 of the mandrel 25 to the upper end of'the liner pipe 11.

Swivel connector -26 may be of any convenient form for permitting rotation of the liner hanger 10 without causing rotation of the liner pipe 11, and as shown in the drawings, this may include an external coupling 28 connected to the lower end 27 of the mandrel and having an upwardly facing shoulder 29 for engaging bearings 30 which in turn are engaged by a downwardly facing shoulder 31 on an internal coupling 32 connected to the liner pipe 11.. In this manner the desired free rotation is obtained and appropriate seals may be provided as lhown'ior retaining lubricants and excluding foreign materials to insure this free rotation. Thus, the only reistance to rotation by drill pipe 14 is that which is busted by liner hanger 10 and, as will hereinafter appear more fully, this resistance is insufiicient to overcome the 4 thread friction resisting unthreading of bushing 23 when the weight of the liner hanger and the liner pipe are suspended from drill pipe 14. However, when the liner hanger 10 is otherwise supported, such as by the casingengaging slips thereof or by resting the liner pipe 11 on the bottom of the well bore 12, and the weight of the drill pipe 14 is set down on the liner hanger, the ring 19 will engage the upper end 33 of the mandrel 25 forming a thrust bearing between the releasable connector 15 and the mandrel. In this manner the axial forces on the threaded bushing 23 are eliminated and rotation of drill pipe 14 will cause unthreading of bushing 23 from mandrel 25 with the bushing raising within the mandrel to a fully released position as shown in FIG- URE 6. The drill pipe 14 and connected releasable connector 15 may be then lifted from the well leaving the liner hanger 10 and liner pipe 11.

The upper portion of the liner hanger 10 is provided with means that are operable for engaging the interior of the well casing 13 to thereby suspend the liner pipe and, as shown in the drawings, these means may include a plurality of longitudinally extending and circumferentially spaced wedge slips 35, with four such wedge slips spaced 90 apart being shown in the drawings. A pair of longitudinally extending ribs 36 are integrally formed with or joined to the mandrel 25 for movably supporting each of the wedge slips and a fluid flow channel 37 is formed between each of the pairs of ribs 36. Referring in further detail to FIGURE 9, each wedge slip 35 has an arcuate outer gripping surface 38 of an appropriate curvature for engaging the inner surface of the casing 13 and the profile of surface 38 is a downwardly facing saw tooth configuration for tightly engaging the well casing against downward movement of the liner hanger. Each side of a wedge 35 is provided with a plurality of projections 39 having inclined surfaces 40 extending upwardly and outwardly. These projections 39 and surfaces 40 engage mating slots 41 and surfaces 42 provided in each of the ribs 36 whereby longitudinally upward movement of a wedge slip 35 causes outward movement of that wedge slip and corresponding reverse movement. Surfaces 40 and 42 are inclined at an appropriate angle so that with the wedge slips 35 engaging the well casing downward movement of mandrel 25 will cause tighter engagement and upward movement of the mandrel will cause releasing of the wedge slips. The lower end of each wedge slip 35 is bifurcated to form a connection clevis 43 and a lateral hole 44 is provided in the clevis.

In order to uniformly actuate the plural wedge slips 35 and latch same in the retracted position illustrated in FIGURE 2a, a tubular latching collar 45 is slidably mounted on the exterior of mandrel 25 below the mounting of ribs 36. A plurality of connection links 46, equal in number to the number of wedge slips 35, are pivotally connected to the clevis 43 of each of the wedge slips 35 by pins 47 through the holes 44. The lower end of each link 46 is pivotally connected in a slot in latching collar 45 by a lateral pin 48 afiixed-to the collar 45. The collars 45 and mandrel 25 are provided with means for releasably latching the collar 45 in the lowermost position to retain the wedge slips 35 in the retracted position and, as shown in the drawings, these may include a pair of downwardly extending spring fingers 49 and 50 integrally formed of the thin walled material of collar 45. Fingers 49 and 50 are integrally formed by machining a pair of spaced downwardly extending slots 51 for each spring finger, as best shown in FIGURE 11. One spring finger 49 is shorter than the other spring finger 50 for reasons that will appear more fully hereinafter. The lower free end of each of the fingers 49 and 50 is provided with an upwardly facing inner abutment 52 and 53, respectively, and an outwardly and downwardly extending tapered end surface 54 and 55, respectively. A pair of lateral grooves 56 and 57 oriented adjacent the spring fingers 49 and 50, respectively, and longitudinally offset from each other have downwardly facing abutments for engaging the longitudinally offset abutments 52 and 53, respectively, at the same position of latch collar 45. With the fingers 49 and 50 engaged in the grooves 56 and 57, respectively, the wedge slips 35 are maintained in the retracted position shown in FIGURE 2a.

Means are provided for frictionally engaging the well casing 13 for producing suflicient frictional drag to accomplish various steps of relative motion of the components of the liner hanger and, as shown in the drawings, these means may include a pair of axially spaced collars 60 and 61 both slidably and rotatably mounted on the tubular mandrel 25 with a plurality of circumferentially spaced springs bows 62 extending longitudinally between and connecting the collars 60 and 61. The spring bows 62 may be of any convenient form and are of sufficiently heavy construction and outwardly bowed configuration (when unstressed) as to produce a substantial drag force due to engagement with the well casing upon either reciprocal or rotational movements. The upper end of the upper collar 60 is provided with a surface 63 of plural circumferential serrations or ridges and a nose portion 64 both for engaging the spring fingers 49 and 50 ofthe latching collar 45 under given circumstances hereinafter described in further detail. In the running-in condition the nose portion 64 of the upper collar 60 is spaced substantially below the spring fingers 49 and 50.

Means are provided for releasably retaining the frictional actuation means formed by collars 60 and 61 and bows 62 within a limited range of axial movement during running-in of the liner pipe and liner hanger and, as shown in the drawings, these means may include a cage member 65 connected to the lower collar 16 and having means for connecting the mandrel 25. A sleeve portion 66 of cage member 65 slidably and rotatably engages the exterior of mandrel 65 and fits within a downward extension 67 of the lower collar 61. Sleeve portion 66 is provided with a plurality of longitudinally extending slots 68 for mating with a like plurality of pins 69 fixedly mounted to and extending inwardly of collar extension 67. This permits axial movement of cage member 65 relative to collar 61 for a predetermined limited distance. The lower end of cage member 65 is comprised of a plurality of downwardly extending integral staves 70 formed by machining circumferentially spaced slots 71 from the tubular form of the cage member 65. The lower portions of the staves 70 are provided with an internal thread 72 of the general type known as wicker or buttress threads. A collar 73 is mounted on mandrel 25 and is provided with an external thread 74 for mating with the internal thread 72 on the staves 70. The mating threads 72 and 74 are right-handed pitched, whereby righthanded rotation of the mandrel (clockwise as viewed from above) while preventing rotation of cage member 65 will cause unthreading and upward movement of cage member 65 from the threaded collar 73. The buttress type threads 72 and 74 are oriented as illustrated with the shoulder surface of the internal thread 72 facing up wardly and the shoulder surface of the external thread 74 facing downwardly. Collar 73 is provided with an inwardly tapering surface 75 at the base of the thread 74 for engaging a like taper on the end of each stave 70 for preventing inadvertent outward springing of a stave 70 when the cage member 65 is completely threaded onto the threaded collar 73. Thus, it may be seen from FIG- URES 2a and 2b that as the liner hanger 10 is lowered into the well the spring bows 62 engage the well casing 13 creating frictional drag and the spring bows and connected collars 60 and 61 are pulled through the casing by means of the connection of pins 69 through the slots 68 in sleeve portion 66 of the cage member 65 which is in turn threadedly connected to the collar 73 afiixed to mandrel 25.

It is conventionally desired to hang the liner pipe 11 at a predetermined location which may be a certain distance from the bottom of the well bore 12 whether a few or many feet. Thus, the liner pipe 11 and liner hanger 10 are run-in'on thedrill pipe 14 until the liner pipe touches bottom and then the drill pipe 14 is raised a distance equal to the desired distance from the bottom plus a distance equal to the total mount. of downward. movement of liner hanger 10 that is necessary for setting the liner hanger. At the top of the upward movement of liner hanger 10 and before any downward movement, the various components of the liner hanger. are in the same relative locations as illustrated in FIGURES 2a and 2b except for the components as shown in FIGURE 3. In lifting the mandrel 25 the cage member 65 is lifted, but lifting of the collars and 61 and bows 62 is resisted by the frictional engagement between the bows and the casing 13. Thus, the sleeve portion 66 of cage member will travel upwardly within the extension portion 67 of collar 61 until a shouldering engagement therebetween is accomplished as shown in FIGURE 3. The drill pipe 14 (and consequently the mandrel 25) is then lowered an amount equal to or slightly greater than the length of slot 68 whereby the components of the liner hanger 10 will return to the identical respective conditions illustrated in FIGURES 2a and 2b due to the frictional drag on bows 62 causing the relative axial movement of the collars 60 and 61 and bows 62. The drill pipe 14 is then rotated in a right-handed (clockwise) direction thereby rotating mandrel 2S and threaded collar 73. The frictional engagement of spring bows 62 resists rotation of lower collar 61 which in turn through pins 69 and slots 68 resist rotation of cage member 65 to unthread cage member 65 from the threaded collar 73, as shown partially accomplished in FIGURE 4. The slot and pin engagement between extension 67 of collar 61 and cage member 65 permits the cage member 65 to move freely in an upward direction during this unthreading and therefore there is a negligible resistance to the upward unthreading movement of the cage member 65. This is to be contrasted with the substantial frictional forces that would be encountered if cage member 65 were fixedly connected to collars 61 to require forcing the spring bows 62 upwardly during the unthreading motion which would cause outward springing of staves 70 to jump threads instead of unthreading. The predetermined length of slots 68 are such as to permit complete unthreading between internal threads 72 and external threads 74 before bottoming of pins 69 in the slots 68.

To continue the liner hanger setting procedure, the drill pipe 14 (and hence the mandrel 25) is lowered and with cage member 65 free from threaded collar 73, the spring bows 62 retain themselves, collars 60 and 61, and cage member 65 at that location in the well casing 13 during such lowering. The tapered surface 55 of the spring finger 50 engages the nose portion 64 of'collar 60 thereby resiliently urging the spring finger 50 outwardly and out of engagement with the groove 57, as shown in FIG- URE 5a. Since spring finger 49 is shorter than spring finger 50, the latching collar 45' will be retained in this axial position by the engagement of spring finger 49 with groove 56 during this releasing movement of Spring finger 50 and while spring finger 50 rides onto the circumferentially rid-ged surface 63 of collar 60. In this manner it is assured that a spring finger will be engaging the ridged surface 63 for complete retraction of the wedge slips 35 and re-latching of the collar 45 when the liner hanger is intentionally unset for further movement down the casing, as hereinafter more fully described. Additional lowering of the mandrel 25 causes nose portion 64 to engage tapered surface 54 to urge spring finger 49 outwardly and out of engagement with the groove 56, thereby completely unlatching the collar 45 from the mandrel 25. Further downward movement of the mandrel 25 causes relative upward movement of the collar 45 and wedge slips 35 which in turn causes outward movement of the wedge slips 35 into engagement with the Well casing as shown in FIGURE 6. The liner hanger 10 is now in the set .condition for suspending the liner pipe 11 therefrom and the drill pipe 14 and releasable connector 15 may be manipulated in the afore-described manner for releasing the drill pipe from the liner hanger.

, However, if it is determined that the liner hanger is hung in an improper location in the well casing :13, the liner hanger may be unset before releasing of the drill pipe 14 and reset in the proper location. This is accomplished by pulling upwardly on the drill pipe 14 which, due to the aforementioned angular movement of the wedge slips 35, will cause releasing of the wedge slips 35 by relative downward and inward movement thereof. The frictional drag of springbows 62 will retain collar 60 and latching collar 45 at this location in the well casing upon further upward movement of the mandrel due to the afore-mentioned interengagement between spring fingers 49 and 50 with the ridged surface 63. This relative motion completely retracts the wedge slips and when further downward movement of latching collar is prevented by the interconnection through links 46 to the ret-racted wedge slips, the .spring fingers 49 and 50 sequentially ride oil": the ridge surface 63 and spring inwardly back into engagement with the grooves 56 and 57, respectively. Further, continued upward movement of the mandrel 25 causes the threaded collar 73 to come into eng-agement with the staves 70 of the cage member 65 thereby lifting the hanging member 65 until it firmly engages the extension 67 of collar 61 and then the staves 70 resiliently spring outwardly to ratchet over the external thread 74 on the collar 73 to the position shown in FIG- URE 7. It is to be noted that the lower ends of the staves 70 will probably not firmly engage the inwardly tapered surface as was the original running-in condition where the cage member 65 was threaded onto the collar 73, but the interengagement of the buttress threads 72 and 74 is completely adequate for pulling downward-1y against the frictional resistance of the spring bows 62 upon lowering of the mandrel 25. By this unsetting operation, the components of the liner hanger 10 have been returned to the conditions illustrated in FIGURES 2a and 2b-except for this last-mentioned spacing between staves 70 and tapered surface 75 and, therefore, the liner hanger is in running-in condition for relocation as desired. Resetting of the liner hanger is accomplished in the identical manner as heretofore described whether or not the liner hanger has been set previously.

Referring now more particularly to the modified arrangement of this invention shown in FIGURE 10, the liner hanger 10a is substantially the same in all functional respects as the heretofore described liner hanger 10. However, the upper end of mandrel 25a is provided with appropriate means for connecting to a releasing tool, generally designated 80, of a type different than the heretofore described releasable connector 15. Releasing tool isin turn connected to the drill pipe 14a which serves the same function as heretofore described drill pipe 14. While the releasing tool 80 may be of any type to accomplish the required functions, it is preferred to use the tool disclosed in the co-tpending patent application entitled Liner Releasing Tool, now issued as Patent No. 3,136,367, and assigned to the assignee of this application. Briefly, the liner releasing tool of that application has means for direct transmission of rotation therethrough when the tool is extended by weight hanging below the tool and yet when weight is set down on the tool right-handed rotation serves to release the tool from the connection there- .bclow similar to the aforedescribed releasing accomplished by releasable connector 15. Thus, since positive rotary motion will be transmitted through releasing tool 80 when the liner hanger 10a and liner pipe 11a are suspended it it is unnecessary to provide-the afore-described mot 26 between the hanger and the liner pipe and instead a simple coupling collar 81 may be employed. manner the drill pipe, liner hanger, and liner pipe my be freely rotated before setting of the liner hanger without the possibility of inadvertent releasing of the liner hanger as might occur under adverse conditions when using the releasable connector '15.

Thus, with liner hanger 10a and releasing tool 80 it is possible to employ the sometimes more desirable rotating type scratchers 82 on the liner pipe 11a for use in conditioning the well bore 12a and drilling fluid prior to the cementing operation. In comparison, with the arrangement of the liner hanger 10, releasable connector 15, and swivel connector 26, it is necessary to use reciprocating type scratchers, wipers, and turbulence-generating devices on liner pipe 11 since rotation is not transmitted through the liner hanger to the liner pipe. It may be seen that by properly positioning the liner hanger 10a without setting same, before the rotation for conditioning the well bore and drilling fluid is initiated, the cage members 65a will be released from threaded collars 73a during the first rota-tions and then it is merely necessary to lower the liner hanger for setting same with the tool 80 being thereafter released by some additional rotation. It is to be noted also that liner hangers 10, 10a, cannot be set by mere reciprocation without prior rotation to release cage member 65, 65a and that under any circumstances of setting of the liner hanger it is merely necessary to lift up to unset and re-latch same.

Having fully described my invention it is to be understood that I do not wish to be limited to the details herein set forth or to the details illustrated in the drawings, but my invention is of the full scope of the appended claims.

I claim:

1. In a liner hanger for supporting a depending liner pipe within a well casing, the combination of: a tubular mandrel, casing-engaging means mounted on said mandrel for longitudinal movement between a retracted position and a casing-engaging position, frictional-drag means rotatably and slidably mounted on said mandrel for frictionally engaging the inside of the well casing, interconnecting thread means mounted on said mandrel and said frictional-drag means with one of said thread means split longitudinally and expandable-collapsible radially for being axially forced into said threaded interconnection and the said mounting of one of said thread means causing free lost-motion longitudinal movement during unthreading of said thread means whereby said mandrel and said frictional-drag means are releasable upon substantial relative rotation and engageable upon simple relative axial movement, and means for longitudinally moving said casing-engaging means from said retracted position into the casing-engaging position after releasing rotation of said interconnecting thread means and axial movement of said frictional-drag means to a sec-0nd position toward said casing-engaging means.

2. The combination of claim 1 in which a pipe is connected through a releasable tool to said mandrel for causing reciprocal and rotational movement of the liner hanger, and said tool includes a spline-driven and longitudinally movable collar having left-handed threads threadedly connected to the liner hanger for releasing by right-handed rotation and a thrust bearing means for engaging the mandrel upon placing weight of said pipe down on said tool.

3. The combination of claim 2 wherein a freely-rotatable swivel connects said mandrel to the liner pipe for rotation of the mandrel and non-rotation of the liner pipe upon rotation of said pipe.

, 4. The combination of claim 2 wherein said releasable tool has means for causing rotation of said mandrel only when said mandrel is suspended from said releasable tool.

5. In a liner hanger for supporting a depending liner pipe within a well casing, the combination of: a tubular mandrel, casing-engaging means mounted on said mandrel for longitudinal movement between a retracted position and casing-engaging position, frictional-drag means rotatably and slidably mounted on said mandrel for frictionally engaging the inside of the well casing, means connected to said firictional-drag means for rotation therewith and a limited distance of axial movement relative thereto, intermatin-g means on said mandrel and said lastmentioned means for releasing upon substantial relative rotation and engageable upon simple relative axial movement toward each other, and means for longitudinally moving said casing-engaging means from said retracted position into the casing-engaging position after releasing rotation of said intermating means causing axial movement of said means connected to said firictional-drag means and axial movement of said frictional-drag means to a second position toward said casing-engaging means.

6. In a linear hanger for supporting a depending liner pipe within a well casing, the combination of: a tubular mandrel, casing-engaging means mounted on said mandrel for longitudinal movement between a retracted position and a casing-engaging position, latch means for retaining said casing-engaging means in said retracted position, frictional-drag means rotatably and slidably mounted on said mandrel for frictionally engaging the inside of the Well casing, means connected to said frictional-drag means for rotation therewith and axial movement relative thereto, intermating means on said mandrel and said last mentioned means for releasing upon substantial relative rotation and engageable upon simple relative axial movement toward each other, and means on said frictional-drag means for releasing "the said latch means and longitudinally moving said casing-engaging means into the casing-engaging position after releasing rotation of said intermating means and axial movement of said frictional-drag means toward said casing-engaging means to a second position. I

7. In a liner hanger for supporting a depending liner pipe within a well casing, the combination of: a tubular mandrel, casing-engaging means movably mounted on said mandrel for longitudinal movement between a retracted position and a casing-engaging position, frictionaldrag means rotatably and slidably mounted on said mandrel for frictionally engaging the inside of the well casing, thread means fixed on said mandrel, second thread means slidably and rotatably mounted on said mandrel for mating with and rotationally releasing from the first said thread means, said two thread means having radiallyexpandable-collapsible means for causing threaded mating of the two thread means upon simple axial movement of said second thread means toward said first thread means, means connecting said second thread means to said frictional-drag means for simultaneous rotational movement therewith and free axial relative movement therebetween for a limited distance for retaining said frictional-drag means in a first longitudinal position with said two thread means in mating engagement, and means for longitudinally moving said casing-engaging means into the casing-engaging position after rotational disengagement of said two thread means with free axial movement of said frictional-drag means toward said casingengaging means.

8. In a liner hanger for supporting a depending liner pipe within a well casing, the combination of: a tubular mandrel, a plurality of casing-engaging means mounted on said mandrel for longitudinal movement between a retracted position and a casing-engaging position for supporting the liner, latch means for retaining said casingengaging means in said retracted position, frictional-drag means rotatably and slidably mounted on said mandrel for fricti-onally engaging the inside of the well casing, external thread means fixed on said mandrel, internal thread means slidably and rotatably mounted on said mandrel for mating with and rotationally releasing from the said external thread means, said internal thread means having means for causing threaded mating of said two thread means upon axial movement of said internal thread means toward and over said external thread means, said internal thread means connected to said frictionaldrag means for retaining said frictional-drag means in a first position spaced from said latch means with said two thread means in mating engagement, and means on said frictional-drag means for releasing the said latch means and longitudinally moving said casing-engaging means into the casing-engaging position after rotational disengagement of said two thread means and axial movement of said frictional-drag means to a second position toward said casing-engaging means and latch means.

9. In a liner lhanger for supporting a depending liner pipe within a well casing, the combination of: a tubular mandrel, casing-engaging means mounted on said mandrel for longitudinal movement between a retracted position and a casing-engaging position for supporting the liner, frictional-drag means rotatably and slidably mounted on said mandrel for frictionally engaging the inside of the Well casing, external buttress thread means fixed on said mandrel, a cage member slidably and rotatably mounted on said mandrel and having longitudinally extending and circumferentially spaced staves with internal buttress thread means for mating with the said external thread means, said staves resiliently movable outwardly for axial sliding of said internal thread means toward and over said external thread means for mating threaded engagement without rotation, means connecting said cage member connected to said frictional-drag means for rotation therewith and limited longitudinal movement therebetween for retaining said frictional-drag means in a first position with said two thread means in mating engagement and for free axial movement of said cage member to threadedly release said two thread means upon rotation of said mandrel, means for longitudinally moving said casing-engaging means into the casing-engaging position after said threaded releasing of said two thread means and upon axial movement of said frictional-drag means along said mandrel to a second position.

10. In a liner hanger for supporting a depending liner pipe within a well casing, the combination of: a tubular mandrel, a plurality of casing-engaging means mounted on said mandrel for longitudinal movement between a retracted position and a casing-engaging position for supporting the liner, latch means connected to said casingengaging means for locking on said mandrel and retaining said casing-engaging means in said retracted position, frictional-drag means rotatably and slidably mounted on said mandrel for frictionally engaging the inside of the well casing, external buttress thread means fixed on said mandrel, a cage member slidably and rotatably mounted on said mandrel and having longitudinally extending and circumferentially spaced staves with internal buttress thread means for mating with the said external thread means, said staves resiliently movable outwardly for axial sliding of said internal thread means toward and over said external thread means for mating threaded engagement without rotation, said cage member connected to said frictional-drag means for retaining said frictional-drag means in a first position with said two thread means in mating and threadedly releasing said two thread means upon rotation of said mandrel, means interconnecting said cage member and frictional-drag means for rotational drive and axial movement therebetween, and means on said frictional-drag means for releasing the said latch means and moving said casing-engaging means into the casing-engaging position after said threaded releasing of said two thread means upon axial and movement of said frictional-drag means along said mandrel toward said casing-engaging means to a second position.

11. In a liner hanger for suspending a liner pipe within a well casing, the combination of: a tubular mandrel having upper and lower ends with the lower end connected to the liner pipe, a plurality of circumferentially spaced wedge slips mounted on said mandrel near the upper end for longitudinal movement between a retracted position and a casing-engaging position, a latch collar slidably mounted on said mandrel below said wedge slips and having means for engaging said mandrel and retaining the wedge slips in said retracted position, frictionaldrag means rotatably and slidably mounted on said mandrel for frictionally engaging the inside of the well casing, means on said frictional-drag means for engaging said latch collar upon axial movement along said mandrel for releasing said means engaging the mandrel and moving the wedge slips to said casing-engaging position, a cage member slidably and rotatably mounted on said mandrel, interconnecting means on said cage member and said frictional-drag means for minimal relative rotation therebetween and for a preselected distance of relative axial movement therebetween, said cage member having a plurality of downwardly extending staves of limited circumferential width, an internal buttress thread on said staves, an external buttress thread on said mandrel near said lower end for mating with said internal buttress thread on said staves for locking said frictional-drag means from engagement with said latch collar and for threadedly releasing the cage member by rotation of said mandrel to set the wedge slips upon axial movement of said mandrel, and said threaded engagement being axially shorter than said preselected distance of axial movement of said cage member relative to said frictional-drag means for free axial movement of said cage member throughout the thread-releasing rotation.

12. In a liner hanger for suspending a liner pipe within a well casing, the combination of: a tubular mandrel having upper and lower ends with the lower end for connecting to the liner pipe, :a plurality of circumferentially spaced wedge slips mounted on said mandrel near the upper end for longitudinal movement between retracted and casing-engaging positions, a latch collar slidably mounted on said mandrel below said wedge slips and having means connected to said wedge slips for causing longitudinal movement of said wedge slips corresponding to axial movement of said latch collar, downwardly facing abutments on said mandrel at the mounting of said latch collar, said latch collar having spring finger means for engaging the said downwardly facing mandrel abutments and retaining the wedge slips in said retracted position against upward movement, a downwardly and outwardly tapered surface on the lower end of each said spring finger means, a pair of axially spaced collars slidably and rotatably mounted on said mandrel below said latch collar, a plurality of circumferentially spaced spring bows extending between and connected to said pair of collars and bowed outwardly to frictionally engage the well casing, the upper of said pair of axially spaced collars having an upper end for engaging said tapered surfaces and urging said spring fingers outwardly from engagement with said mandrel abutments and moving said wedge slips to the casing-engaging position, and intermating means on said mandrel and the lower of said pair of collars for releasing upon substantial relative rotation of said mandrel and reengaging upon simple axial movement toward each other for restraining the upper of said pair of spaced collars from engagement with said latch collar finger means before rotational releasing.

13. In a liner hanger for suspending a liner pipe within a well casing, the combination of: a tubular mandrel having upper and lower ends with the lower end for connecting to the liner pipe, a plurality of circumferentially spaced wedge slips mounted on said mandrel near the upper end for longitudinal movementbetween retracted and casing-engaging positions, a latch collar slidably mounted on said mandrel below said wedge slips and lnving means connected to said wedge slips for causing longitudinal movement of said wedge slips corresponding to axial movement of saidlatch collar, a pair of downwardly facing abutmentson saidmandrel at the mountill said latch collar and circumferentially spaced from each other, said latchcollar having a pair of spring We each having an internal upwardly facing abutment I thesaidpair of downwardly facing mandrel abutments and retaining the wedge slips in said retracted position against upward movement, a downwardly and outwardly tapered surface on the lower end of each said finger with said surfaces being longitudinally offset from each other, frictional-drag means rotatably and slidably mounted on said mandrel below said latch collar for frictionally engaging the inside of the wall casing, the upper end of said frictional-drag means having annular means for sequentially engaging said tapered surfaces and urging said pair of fingers outwardly to disengage said pairs of abutments upon upward movement and continued upward movement of said frictional-drag means causing movement of said latch collar and wedge slips to the casingengaging position, means connected to said frictional-drag means for rotation therewith and axial movement relative thereto, and intermating means on said mandrel and said last-mentioned means for releasing upon substantial relative rotation and engageable upon simple relative axial movement toward each other.

14. In a liner hanger for suspending a liner pipe within a well casing, the combination of: a tubular mandrel hav ing upper and lower ends with the lower end for connecting to the liner pipe, a plurality of circumferentially spaced wedge slips mounted on said mandrel near the upper end for longitudinal movement between retracted and casing-engaging positions, a latch collar slidably mounted on said mandrel below said wedge slips and having means connected to said wedge slips for causing longitudinal movement of said wedge slips corresponding to axial movement of said latch collar, a pair of downwardly facing abutments on said mandrel at the mounting of said latch collar and circumferentially spaced from each other, said latch collar having a pair of spring fingers each having an internal upwardly facing abutment for engaging the said pair of downwardly facing mandrel abutments and retaining the wedge slips in said retracted position against upward movement, a downwardly and outwardly tapered surface on the lower end of each said finger with said surfaces being longitudinally offset from each other, frictional-drag means rotatably and slidably mounted on said mandrel below said latch collar for frictionally engaging the inside of the well casing, the upper end of said frictional-drag means having annular means for sequentially engaging said tapered surfaces and urging said pair of fingers outwardly to disengage said pairs of abutments upon upward movement and continued upward movement of said frictional-drag means causing movement of said latch collar and wedge slips to the casingengaging position, a cage member slidably and rotatably mounted on said mandrel, below said frictional-drag means, interconnecting means on said cage member and said frictional-drag means for minimal relative rotation therebetween and for a preselected distance of relative axial movement therebetween, said cage member having a plurality of downwardly extending staves of limited circumferential width, an internal buttress thread on said staves, an external buttress thread on said mandrel near said lower end for mating with said internal buttress thread on said staves for locking said frictional-drag means from engagement with said latch collar fingers and for threadedly releasing the cage member by rotation of said mandrel to set wedge slips upon axial movement of said mandrel, and said threaded engagement being axially shorter than said preselected distance of axial movement of said cage member relative to said friction-drag means for free axial movement of said cage member throughout the thread-releasing rotation.

15. In a liner hanger for suspending a liner pipe within a well casing, the combination of: a tubular mandrel having upper and lower ends with the lower end for connecting to the liner pipe, a plurality of circumferentially spaced wedge slips movably mounted on said mandrel near the upper end, cooperation of the mounting means on said mandrel and said wedge slips for causing outward movement Of said wedge slips from a retracted position into a position of engagement with the well casing upon longitudinal upward movement of said wedge slips relative to said mandrel, a latch collar slidably mounted on said mandrel below said wedge slips and having means connected to said Wedge slips for causing longitudinal movement of said wedge slips corresponding to axial movement of said latch collar, a pair of downwardly facing abutments on said mandrel at the mounting of said latch collar and being circumferentially spaced and longitudinally offset from each other, said latch collar having a pair of integrally formed spring fingers each having an internal upwardly facing abutment for engaging the said pair of downwardly facing mandrel abutments and retaining the wedge slips in said retracted position against upward movement, a downwardly and outwardly tapered surface on the lower end of each said finger with said surfaces being longitudinally offset from each other, a pair of axially spaced collars slidably and rotatably mounted on said mandrel below said latch collar, a plurality of circumferentially spaced spring bows extending between and connected to said pair of collars and bowed outwardly to frictionally engage the well casing, the upper of said pair of axially spaced collars having an annular upper end for sequentially engaging said tapered surfaces and urging said pair of fingers outwardly to disengage said pairs of abutments, said annular upper end having circumferential ridges for releasably retaining said disengaged fingers thereon upon downward movement of said spaced collars for retracting said wedge slips, a cage member slidably and rotatably mounted on said mandrel below said pair of spaced collars, pin and longitudinal slot interconnecting means on said cage member and the lower of said pair of spaced collars for minimal relative rotation therebetween and for a preselected distance of relative axial movement therebetween, said cage member having a plurality of downwardly extending staves of limited circumferential width, an internal buttress thread on said staves, and an external buttress thread on said mandrel for mating with said internal buttress thread on said staves for locking said pair of spaced collars to the mandrel away from engagement with said latch collar fingers and for threadedly releasing the cage member by rotation of said mandrel, said external thread being axially shorter than said preselected distance of axial movement of said cage member relative to said lower collar for free axial movement of said cage member throughout the threadreleasing rotation.

References Cited by the Examiner UNITED STATES PATENTS 1,593,909 7/1926 Nixon 166l39 2,182,549 12/1939 Brumbly l66139 X 2,303,556 12/1942 Johnson et al. 166139 X 3,097,697 7/1963 States 166138 3,171,490 3/1965 States 166-139 CHARLES E. OCONNELL, Primary Examiner.

I. A. LEPPINK, Assistant Examiner. 

1. IN A LINER HANGER FOR SUPPORTING A DEPENDING LINER PIPE WITHIN A WELL CASING, THE COMBINATION OF: A TUBULAR MANDREL, CASING-ENGAGING MEANS MOUNTED ON SAID MANDREL FOR LONGITUDINAL MOVEMENT BETWEEN A RETRACTED POSITION AND A CASING-ENGAGING POSITION, FRICTIONAL-DRAG MEANS ROTATABLY AND SLIDABLY MOUNTED ON SAID MANDREL FOR FRICTIONALLY ENGAGING THE INSIDE OF THE WELL CASING, INTERCONNECTING THREAD MEANS MOUNTED ON SAID MANDREL AND SAID FRICTIONAL-DRAG MEANS WITH ONE OF SAID THREAD MEANS SPLUT LONGITUDINALLY AND EXPANDABLE-COLLAPSIBLE RADIALLY FOR BEING AXIALLY FORCED INTO SAID THREADED INTERCONNECTION AND THE SAID MOUNTING OF ONE OF SAID THREAD MEANS CAUSING FREE LOST-MOTION LONGITUDINAL MOVEMENT DURING UNTHREADING OF SAID THREAD MEANS WHEREBY SAID MANDREL AND SAID FRICTIONAL-DRAG MEANS ARE RELEASABLE UPON SUBSTANTIAL 